Wrenn, B. (1988). Instructor's manual: marketing management: Analysis, planning, implementation, and control (6th ed.). Prentice-Hall.
Παραπομπή σε μορφή Chicago (17η εκδ.)Wrenn, Bruce. Instructor's Manual: Marketing Management: Analysis, Planning, Implementation, and Control. 6th ed. Englewood Cliffs, N.J: Prentice-Hall, 1988.
Παραπομπή σε μορφή MLA (9th εκδ.)Wrenn, Bruce. Instructor's Manual: Marketing Management: Analysis, Planning, Implementation, and Control. 6th ed. Prentice-Hall, 1988.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.